Add an XPC service to handle alert notifications on mac

chrome/browser/ui/cocoa/notifications/alert_notification_service.mm

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "chrome/browser/ui/cocoa/notifications/alert_notification_service.h"
+
+#import "base/mac/scoped_nsobject.h"
+#import "chrome/browser/ui/cocoa/notifications/notification_builder_mac.h"
+
+@class NSUserNotificationCenter;
+
+@implementation AlertNotificationService
+
+- (void)deliverNotification:(NSDictionary*)notificationData {
+  base::scoped_nsobject<NotificationBuilder> builder(
+      [[NotificationBuilder alloc] initWithDictionary:notificationData]);
+
+  NSUserNotification* toast = [builder buildUserNotification];
+
+  [[NSUserNotificationCenter defaultUserNotificationCenter]
+      deliverNotification:toast];
+}
+
+@end